Effects of varying virus-spiking conditions on a virus-removal filter Planova™ 20N in a virus validation study of antibody solutions.
ABSTRACT We aimed to investigate the effect of virus-spiking conditions on the filter performance (flux, flux decay, and parvovirus reduction) of the small virus filter Planova™ 20N. We used three kinds of porcine parvovirus (PPV) stocks: serum, serum-free, and purified. The flux profile with PPV spiking was similar to that without spiking for normal load filtration of about 250-300 L/m(2) . High volume (3 vol %) of serum-free PPV and 1 vol % serum PPV reduced the flux to some extent for high-load filtration (over 10 h, ca., 500 L/m(2) , 5 mg/mL IgG solution). Log reduction value (LRV) of PPV was maintained at a high level (>5) over the filtration volume. Flux for Planova™ 20N was only minimally affected by the use of different virus stocks for spiking. Transmission electron microphotography showed that the distribution of PPV particles captured inside the membrane wall was reached until the -60% thickness of the membrane, showing that the membrane of Planova™ 20N has a thick effective layer for virus removal. These results provided evidence for the robustness of the filter performance of Planova™ 20N, showing that it was not easily affected by virus spiking conditions and that it has a large capacity for high-load conditions.
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ABSTRACT: Viral filtration is routinely incorporated into the downstream purification processes for the production of biologics produced in mammalian cell cultures (MCC) to remove potential viral contaminants. In recent years, the use of retentive filters designed for retaining parvovirus (˜20 nm) has become an industry standard in a conscious effort to further improve product safety. Since retentive filters remove viruses primarily by the size exclusion mechanism, it is expected that filters designed for parvovirus removal can effectively clear larger viruses such as retroviruses (˜100 nm). In an attempt to reduce the number of viral clearance studies, we have taken a novel approach to demonstrate the feasibility of claiming modular retrovirus clearance for Asahi Planova 20N filters. Porcine parvovirus (PPV) and xenotropic murine leukemia virus (XMuLV) were co-spiked into six different feedstreams and then subjected to laboratory scale Planova 20N filtration. Our results indicate that Planova 20N filters consistently retain retroviruses and no retrovirus has ever been detected in the filtrates even when significant PPV breakthrough is observed. Based on the data from multiple in-house viral validation studies and the results from the co-spiking experiments, we have successfully claimed a modular retrovirus clearance of greater than 6 log10 reduction factors (LRF) to support clinical trial applications in both USA and Europe. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 2013.Biotechnology Progress 10/2013; · 1.85 Impact Factor
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ABSTRACT: Virus-removal filtration technology is commonly used in the manufacturing process for biologics to remove potential viral contaminants. Virus-removal filters designed for retaining parvovirus, one of the smallest mammalian viruses, are considered an industry standard as they can effectively remove broad ranges of viruses. It has long been observed that the performance of virus filters can be influenced by virus preparations used in the laboratory scale studies (PDA, 2010). However, it remains unclear exactly what quality attributes of virus preparations are critical or indicative of virus filter performance as measured by effectiveness of virus removal and filter capacity consistency. In an attempt to better understand the relationship between virus preparation and virus filter performance, we have systematically prepared and analyzed different grades of parvovirus with different purity levels and compared their performance profiles on Viresolve® Pro parvovirus filters using four different molecules. Virus preparations used in the studies were characterized using various methods to measure DNA and protein content as well as the hydrodynamic diameter of virus particles. Our results indicate that the performance of Viresolve® Pro filters can be significantly impacted depending on the purity of the virus preparations used in the spike and recovery studies. More importantly, we have demonstrated that the purity of virus preparations is directly correlated to the measurable biochemical and biophysical properties of the virus preparations such as DNA and protein content and monodispersal status, thus making it possible to significantly improve the consistency and predictability of the virus filter performance during process step validations. Biotechnol. Bioeng. © 2012 Wiley Periodicals, Inc.Biotechnology and Bioengineering 07/2012; · 3.65 Impact Factor